renderLine method
Implementation
void renderLine(CanvasRenderingContext2D ctx) {
points.clear();
ctx
..beginPath()
..strokeStyle = '#3366cc';
var x = axis.style.leftMargin.toDouble();
var y = height -
axis.style.bottomMargin -
(data.first.value - axis.yFrom) / axis.yScaleValue;
points.add(ChartPoint(x, y, data.first));
ctx.moveTo(x, y);
for (var i = 1; i < data.length; i++) {
final dataRow = data[i];
x = axis.style.leftMargin + axis.xStepPix * i;
y = height -
axis.style.bottomMargin -
(dataRow.value - axis.yFrom) / axis.yScaleValue;
ctx.lineTo(x, y);
points.add(ChartPoint(x, y, dataRow));
}
ctx.stroke();
}